Google has a mashup editor. Microsoft has a mashup editor. Yahoo has a mashup editor. And then there's Piggy bank, which is open source. "Piggy Bank is a Firefox extension that turns your browser into a mashup platform, by allowing you to extract data from different web sites and mix them together. Piggy Bank also allows you store this extracted information locally for you to search later and to exchange at need the collected information with others." Via Henry Story. See also Mashmaker at Intel (more).